Systems Development Life Cycle: SDLC is a Disciplined approach to systems development There are many version of SDLC (nearly as many as authors)

Systems Development Life Cycle (SDLC) Building an IS Basic Idea (solution to a problem) Blueprint is designed presenting detailed information about the system System implementation The SDLC four phases: Planning, Analysis, Design, Implementation (support)

A Systems Development Life Cycle: Planning Systems Support Systems Analysis Systems Implementation Systems Design

Systems Development Life Cycle (SDLC) Planning The systems business value to the organisation is identified Documents the business need and the systems support to create business value

Systems Development Life Cycle (SDLC) Planning During project management, the project manager creates a work plan, staffs the project, and puts techniques in place to control and direct the project through the entire SDLC The deliverable for project management is a project plan that describes how the project team will go about developing the system

Systems Development Life Cycle (SDLC) Analysis Answers the questions of who will use the system, what the system will do, and where and when it will be used During this phase, the project team investigates any current system(s), identifies improvement opportunities, and develops a concept for the new system

Systems Development Life Cycle (SDLC) Analysis Analysis begins with the development of an analysis strategy that guides the project teams efforts The next step is the development of a concept for a new system accomplished through information gathering (interviews/questionnaires)

Systems Development Life Cycle (SDLC) Analysis The system concept is then used as a basis to develop a business process model that describes how the business will operate if the new system were developed Finally, a data model is developed to describe the information that is needed to support the process

Systems Development Life Cycle (SDLC) Analysis The system proposal is presented to the project sponsor and other key decision makers who decide whether the project should continue The system proposal is the initial deliverable that describes the new system

Systems Development Life Cycle (SDLC) Design Decide how the system will operate, in terms of the hardware, software, and network infrastructure, the user interface, forms, and reports that will be used; and the specific programs, databases, and files that will be needed

Systems Development Life Cycle (SDLC) Design The first step in the design phase is to develop the design strategy (develop the system in-house; outsource the development; purchase an existing off-the-shelf software package) This leads to the development of the basic architecture design for the system that describes the hardware, software, and network infrastructure

Systems Development Life Cycle (SDLC) Design The interface design specifies how the users will move through the system (navigation methods such as menus and on-screen buttons) and the forms and reports that the system will use

Systems Development Life Cycle (SDLC) Design Finally, the analysis team develops the program design which defines the programs that need to be written and exactly what each program will do The collection of deliverables (architecture design, interface design, database and file specifications, and program design) is the system specification that is handed to the programming team for implementation

Systems Development Life Cycle (SDLC) Design At the end of the design phase, the feasibility analysis and project plan are reexamined and revised and another decision is made by the project sponsor and approval committee about whether to terminate the project or continue

Systems Development Life Cycle (SDLC) Implementation The final phase in the SDLC, during which the system is actually built (or purchased) This is the phase that usually gets the most attention, because for most systems it is the longest and most expensive single part of the development process The first step is system construction, during which the system is built and tested to ensure it performs as designed

Systems Development Life Cycle (SDLC) Implementation Testing is one of the most critical steps in implementation (huge cost of bugs and errors) Organisations spend more time and attention on testing than on writing the programs in the first place Once the system has passed a series of tests, it is installed

Questions What are the advantages & disadvantages of this structured approach?

The problem of large development projects Problem – All projects are considered as being equivalent The duration effect Paul Melichar (early 80’s) A slowed pace of development Treatment of the project as a career Loss sight of the original business problem Loss of interest by the development staff

The problem of large development projects Constantly changing user requirements Deterioration of moral Large projects – big failure rate Where implemented – Often inadequate to the end user

The problem of large development projects Unobtainable deadlines Many changes are outside the scope of the original project